# ISS calculator vs SonicKeys

The clearest difference is iOS requirement: ISS calculator at 13.0 against SonicKeys's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ISS calculator ships an update every 3 days, SonicKeys every 2 days. The most recent releases landed on September 22, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | ISS calculator | SonicKeys |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/iss-calculator/id1531086115/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 days | **Every 2 days** |
| Monetization | Free | — |
| Size | 2 MB | 12 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Sujal Adhia](https://appshunter.io/developer/1475334795) | [Yongjun Hong](https://appshunter.io/developer/1893365538) |

## What reviewers say

### ISS calculator

[App page](https://appshunter.io/ios/app/iss-calculator/id1531086115)

This tool helps assess the severity and extent of ichthyosis across the body. It's designed for clinical trials, research, and practice to track treatment response in adults and children. The system follows FDA guidelines for comprehensive scoring.

**Highlights:** Assess ichthyosis extent and severity, User-friendly instrument, For clinical trials and research, Track treatment response, Score adults and children, Follows FDA guidelines

**Features:** macOS Compatibility

**In-app purchases:** none


### SonicKeys

[App page](https://appshunter.io/ios/app/sonickeys/id6762207609)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is ISS calculator free?

ISS calculator is free to download, with no in-app purchases.

### Is SonicKeys free?

SonicKeys is free to download, with no in-app purchases.

### Do ISS calculator or SonicKeys have ads?

Neither ISS calculator nor SonicKeys shows ads.

### Which is updated more often, ISS calculator or SonicKeys?

ISS calculator ships an update every 3 days, and SonicKeys every 2 days. Most recently, ISS calculator was updated on September 22, 2026 and SonicKeys on October 8, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*